Method of reenforcing hollow bodies formed by electrodeposition



A. K. LAUKEL Feb. 17, 1931.

METHOD OF REENFORCING HOLLOW BODIES FORMED BY ELECTRODEPOSITION 2 Sheets- Sheet l Filed June 21, 1928 A. K. LAUKEL 1,792,542

METHOD OF REENFORCING HOLLOW BODIES FORMED BY ELECTRODEPOSITION Feb. 17, 1931.

Filed June 21, 1928 2 Sheets-Sheet 2 Patented Feb. 17, 1931 ARTHUR K. LAUKEL, on DETROIT, MICHIGAN" METHOD or REEareaeme-sonmwno ies sonnet BY ELECTRODEIOSITION A neatidn filed June 21,

' The presentinvention pertains to anovel method fTEQHfOICiHghUllOW bodies formed by deposition and is adaptedparticularlyfor use in connection with the manufacture of patterns by electro-deposition. Suchbodies or pa-tternsare preferably comprised of an electro-deposited shell which is subsequently filled with suitable fmaterial. It is desirable to maintain the deposited shell at a" minimum thickness, "consistent with l strength, thereby reducing the amount of inie,-. current and l'naterialrequired in'the electro plating process. The cathode on which the deposit forms is in thenature of a mold from which the deposit must be separatedwhen finished. It has been found in practice that the deposit must have. a: definite rigidity, especially at certain points, in order toavoid distortion when the moldis removed. The object of the present invention is to rprovideameans for furnishing such rigidity as Well as anchorage for dowel pinning and screwing, and consists essentially in depositing a bridge across the depression of the mold at those points where reenforcementris desired. The bridge is preferably built of a plastic non conducting material when the deposition has been partly completed. The outer surface of the bridge is rendered conductive, and the plating operation is con-- .30 tinned, whereby a deposited bridge forms as an integral part of the hollow body. a The plastic bridge may then be removed, while the deposited bridge remains as a reenforcement ofth'e hollow body.

Where'the' bridge is to be used as anchorage for a dowel pin or screw, it is made sulfieien-tly thick-fer this purpose and; obviously is'r'etained asa permanent part of the deposit. Such a bridge may consist of a metallic insert, such as brass, united to the main deposit by deposited metal. I

The invention is fully disclosed by way of example in the followingv description and in a theaccompanyingdrawings, in which- Figure 1 is ail-elevation of a mold or cathode prepared for plating;

Fig. 2 is atransverse section of the mold after the first stage of plating;

Fig. 3 is aplan view of the moldafterthe by use of like characters which are employed 1928. serial No. 287,316.

- Fig.*8 section on the line 88 of Fig- 6c ure'6; J

Fig. 9 is a perspective view with the mold a-ndthe completedeposit therein, the latter being severed for separation from the de posit; and i Fig. 10 is a sectional view similar to Figure 8 showing abridge built up in a somewhat different manner;

Reference to'these views will now be made to designate corresponding parts throughout.

- In Figure 1 is illustrated a mold 1 of suitable material formed with a depression or cavity 2, the face of which is rendered conductive and'connected to the negative side of an electric circuit in order to function as a cathode. The preparation of the mold is described in my co-pending application, Serial 108,715, filed May 13, 1926. Over the face of the mold isapplied an insulating sheet 4 having its edges projecting slightly over the depression. This insulator is. retained on the cathode during the initial stages of plating in order to prevent the formation of any deposit above the edge of the depression; This condition is illustrated in Figure 2 which shows a deposit 5 formed in the depression but diminishing in thickness towards the edges and not extending beyond the edges. l r

The cathode is now Withdrawn from the bath in order that the insulator 4 may be removed. Bridges 6rare built across the depression at points where reenforcement is desired for the purposes already stated. These bridges are preferably made of plastic material such as Wax and coated with graphite on the upper or outer surface in order to attract the ions of the metal in the bath. It

will be seen in Figure 4 that the top of the bridge is substantially flush with the face of the mold, so that the deposited bridge will for the most part lie over the face of the mold.

At points where it may be necessary to drive fastening elements through the deposited body, such as screws through a pattern, the bridge 6 is in a lower plane and has its upper surface beneath the face of the mold as shown in Figure 5. Another means of forming anchorage for dowel pins or screws is illustrated in Figure 10 wherein a small block of metal 11, such as brass, is inserted in the deposit and secured to the walls thereof by plastic material 12. The top of the plaslic material is preferably below the top of the insert. The upper surface of the plastic inalerial is rendered conductive, as, is the top of the insert it necessary, in the manner described.

The mold now returned to the bath and electro-plating is resumed until the desired deposit is built up. The complete depositis shown in Figures 6 to 9, wherein a strengthening flange 7 is formed exteriorly around the edge of the deposit and wherein deposited bridges 8 are formed over the plastic bridges 6. If, however, no flange is to be deposited, the insulator 4L need not be removed prior to the second immersion, but it is only necessary to notch the edges of the insulator at the points where the bridge is to be united to the initial deposit. lVhere a sunken bridge 6 has been provided a thicker deposited bridge 9 forms thereon and obviously extends for some distance below the face of the mold. In connection with the method illustrated in Figure 10, a deposit 13 forms over the top and partly covers the ends of the insert 11.

The mold or cathode is now severed along various lines as indicated by the numeral 10 whereby it may be broken away from the deposit. The breaking action causes certain stresses on the deposit, and to resist these stresses the deposit mu st have such reenforcement as has been described.

The subsequent treatment of the deposit, in case it is a pattern, consists in filling it with a cheap, low fusing metal and then machining oil the flange 7 to form a plane parting surface. This operation substantially removed the bridges 8, but it will be understood that these bridges have already served their purpose and are not actually necessary in the finished pattern. The heavier bridges 9 which have been formed for the purpose of anchoring fastening elements obviously remain to the extent of the portion lying beneath the parting surface.

Although the invention has been developed particularly for use in connection with the deposition of patterns, it is obviously useful in the formation of other hollow bodies which may be deposited by the same process. The cathode bridges have been described as consisting of a plastic material coated with graphite, but there is no restriction to this composition, for the bridges may be formed in any manner and of any material which will'provide the desired transverse conductive strip on which a permanent bridge may be deposited. Various other modifications of the disclosed operations may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is 1. In the process of forming a hollow metallic body on a depressed mold by electro-deposition, the operation consisting in building across the depression at a point where reenforcement is desired, a bridge having aconducting surface, whereby a metallic bridge is deposited integrally with the hollow body.

2. In the process of forming a hollow metallic body on a depressed mold by electrodeposition, the operation consisting in building a bridge of non-conducting material across the depressionat a point where reenforcement is desired, and rendering the surface of said bridge conductive, whereby a metallic bridge is deposited integrally with the hollow body.

3. A method of making .reenforced metal hollow bodies consisting in electro-deposition a depressed mold to a portion of the desired thickness of deposit, building across such partial deposit at a point where reenforcement is desired, a bridge having a conductive surface. and continuing the plating whereby a metallic bridge is deposited integrally with the hollow body.

4. A method of making reenforced metal hollow bodies consisting in electro-deposition a depressed mold to a portion of the desired thickness of deposit, building a bridge of nonconductive material across the depression at a point where reenforcement is desired, rendering the surface of said bridge conductive, and continuing the plating whereby. a metallic bridge is deposited integrally with the hollow body.

5. In the process of forming a hollow metallic body on a depressed mold by electrodeposition, the operation consisting in building a bridge of wax across the depression at a point where reenforccment is desired, and rendering the surface of said bridge conducfive, whereby a metallic bridge is deposited integrally with the hollow body.

6. In the process of forming a hollow metallic body on a depressed mold by electrodeposition, the operation consisting in supporting a metal insert across the mold and plating upon said insert and between the insert and the-mold, whereby a metallic bridge is formed and united to the hollow body by deposited metal.

7. In the process of forming a hollow metallic body on a depressed mold by electrodeposition, the operation consisting in supporting a metal insert across the mold'by' plastic material, rendering the surface of said material conductive, and plating on said in? sert and material, whereby a metallic bridge is deposited integrally with the hollow body.

8. In the process of forming a hollow Inetallicbody on a depressed mold by electrodepositiomthe operation consisting in building a bridge of wax across the depression at a point where reenforcement is desired, and applying graphite over the surface of said bridge, whereby a metallic bridge is deposited integrally with the hollow body.

9. A cathode for the formation of a hollow body by electro-deposition, comprising a mold having a depression therein, the Wall 7 of said depression being conductive, and'a 7 2O bridge built across said depression at a point Where reenforcement is desired, said bridge having a conductiveouter surface. 7

In testimony whereof I aflix my signature.

ARTHUR K. LAUKEL. 

